Producing gas wells generate sufficient pressure to carry gas bearing brine to surface. At surface separators are used to separate the gas from the brine. The brine is then trucked to a disposal well and injected into a disposal formation. When a gas well can no longer generate sufficient pressure to carry gas bearing brine to surface, it is generally abandoned.
U.S. Pat. No. 4,377,208 which issued to Elliott et al in 1983 entitled "Recovery of Natural Gas from Deep Brines" discloses a method for downhole separation of natural gas from brine which involves the injection of spent brine into a disposal formation. A release of the natural gas and a circulation of spent brine into a disposal formation is initiated by blowing gas under pressure into the well to displace brine and then releasing the pressure. When the pressure is released, natural gas containing brine rises in the well and, as it rises, releases natural gas. The method can achieve a steady state condition as long as the pressure of the natural gas is greater than the vapour pressure of saturated steam over the brine at formation temperatures. This pressure differential is required in order to reinject the spent brine into the disposal formation. If pressure is returned to atmospheric, the conditions enabling gas lift are destroyed. The method is, therefore, limited in its application to geopressured or hydrostatically pressured brines. Elliott et al suggest that wells suitable for the practising of their method are deep holes in which the temperature at the bottom of the hole approaches 300 degrees fahrenheit. Unfortunately, a relatively small percentage of the natural gas wells have conditions favourable to the successful application of the Elliott et al method.